MINIATURE DRUM MICROSCOPE:

c. Middle third of 19th Century

Unsigned but often attributed to Bertand of Paris

Serial Number: None

DESCRIPTION

This is an example of the diminutive "Furnace" Drum microscope, apparently first popularized by Bertrand of Paris about 1839.
It is very small and its small size makes it a bit difficult to use; for that reason its base dovetails into a slot on the top of its box. In this position, on the box, the entire assembly closely resembles an old furnace (as seen below), hence the name.

HISTORY OF DRUM MICROSCOPES

The drum microscope was apparently invented by the Germans in the first years of the 18th century, but it was Benjamin Martin who refined the design introducing it in England about 1730. The original versions
were first made of cardboard and wood, sometimes with ornate shagreen rayskin covering. The Martin Drum design
is grossly inferior to even early 19th century microscopes, but compared to others remained one of the
least expensive to produce. For this reason the production of drum microscopes, initially non-achromatic, continued for
many years and even into the twentieth century. They were equipped with achromatic objectives by the French, but usually
nonachromatic objectives by the English.

As time passed, the design was limited to small versions but usually about twice the size of the Furnace Microscope and these smaller cheaper ('toy') versions were nearly all produced in France, exported in large numbers; there are several examples of these smaller less expensive drum microscopes in this collection and they continue to
be plentiful on the antique market, even in the twenty-first century. The small cheap versions were still being sold
by Sears in the 1930's.

It is unclear for how long the miniature Furnace microscope was made for, but the author is aware of some that are nickel or chrome-plated, suggesting their production continued long after they were first introduced. Even the original model was still being made in the 1860's. Notice the structure of these 19th century furnaces and the resemblance to the 'Furnace Microscope.'